Cyborgs with computer-augmented brains are the stuff of science fiction, but in recent years they have also become science fact. In this lecture we review the state of the art in connecting brains to computers, including basic research being conducted with animals and clinical research with humans. We then enumerate the ethical issues raised by current and foreseeable uses of these technologies. The goal of this class is to provide a basic understanding of current capabilities of brain-machine interface technology, and of the ethical issues arising from research and clinical uses.